One by one, Gwyneth Paltrow is slowly alienating fellow Hamptonites. The actress was spotted at a J.Crew in East Hampton yesterday, where a spy says she was “extremely rude” to store employees and shoppers.

An on-looker tells Star that when the 40-year-old was checking out, she demanded her usual discount, and wasn’t happy when the employee told her she would get 15% off. “She snapped back at the store clerk that her discount was for 30%,” our source says — and in the end, the diva got what she wanted.

Gywneth’s penny-pinching ways is ironic, considering simple kitchen items she recommends on her website, Goop.com, often start in the thousand-dollar range.

And this isn’t the first time this summer that the Iron Man star made waves while vacationing in the Hamptons. Last week, she attended East Hampton Library’s Authors Night, where fellow author, Christina Oxenberg, slammed the actress’ overbearing presence at the event.

“The divinity in question arrived with hubby, children and a couple of massive bodyguards,” she wrote. “The worshippers blocked my view of the whole world, abusing my tiny territory upon which to abandon their trash or lean their sorry asses.”